Pneumatic-tire safety signal



Dec. l1,4 1926.

J. E. KENNEDY PNEUMATIG TIRE SAFETY SIGNAL Filed July 22, 1925 0A 7 o A 1 6. M40/0n 1 Vf l /7 C, v 29 7, auf 7 f, v

U C Z Patented Dec. 14, 1926.

Pri-snr rifles.

JOHN E. KENNEDY, 0F LOS ANGELES, CALIFORNIA.

PNEUMAVTIG-TIRE SAFETY SIGNAL.

Application filed Julyf22', 1925. Serial No. 45,261.

This invention relates to pneumatic tire safety signals, and is intended to provide a simple, durable and reliable device of this kind adapted to be permanently secured to the tire and have continuous communication with the interior thereof so as to give indication of over-inflation or under-inflation of the tire of such marked visibility as to make the signal visually effectiveI at a distance without close inspection or reading of' a linely marked scale.

The present improvement is a modification or alternativer construction to that shown in my co-pending application for U.

patent filed June 24, 1922y bearing Serial No. 570,661, and embodies a differentform ofv the same principle underlying the device forming the subject matter of said application. i

Since the great majority of motorists will not take the trouble to remove the dust caps of each tire and apply a pressure gauge and thereafter. restore the dust cap, some reliable and practical means of giving such a conspicuous indication of under-inflation or over-inflation of the tire is of great practical importance in view of the great vogue of `balloon tires, that is tires of low pressure and thin flexible walls. Such tires are very injuriously affected both by over-inflation ,and by under-inflation even to a compara tively small degree. y d

The present invention solves that problem by providing pressure-responsive means adapted to be permanently secured to the tire stem and maintained in communication with the compressed air in the tire, combined with display-signaling means of' such a character that it will give. visual warning by means of conspicuous display Nsignals plainly noticeable at a glance, and without close inspection, by means of a pressureresponsive cap arranged to cover the inner end of the device, that is the end toward the center of the wheel, and to eX- pose or conceal fromview, by the edgeof its open end, a display element so conspicuous as to be visible at a distance, thereby dispensing with the close inspection oli' each individual ytire and involving no reading of a line scale.

In the accompanying drawings l have illustrated a `device constructed in accordance with this invention, in which:

Figure 1 is a vertical central section of the device and its attaching coupling for securing it to the tire.

Figure 2 is a side elevation of the device- Figure 3 is a side view, partly in section and partly in elevation, showing the position of the indicator or signaling cap when the tire is under-infiated- Y Figure L l is a view, similar to Figure 3, showing the position of the cap and pressure-responsive means when the tire is over` inflated. .y v Y In the practice of the invention, as herein illustrated, I provide a hollow body forming a compressed air chamber 10, provided with suitable coupling means 11 for permanently but detachably securing it to the stem of the tire, and having an interior boss 12 positioned to engage the stem of the tirevalve and unseat it to allow air v from the tire to flow through communicating passage 13 into the interior of the body or air chamber.

To avoid removal of the device when it is desired to inflate the tire .or to deflate it, a lateral nipple 14 is provided containing the usual air-sealing valve 15. n

A diaphragm 16 of flexible material, impervious to air, is tightly clamped around its periphery against the inner Yend of the Vair chamber 1() or vwhat may be termed the upper end, as shown in the drawings, by means of a covering cap 17 screwed tightly down against van interposed washer. The cover cap has an upward extension forming a plunger casing l'L in which is slidably mounted a plunger sleeve 1S, whose lower end is internally threaded to retain an adj ustable tensioning nut 19, which nut is 'interiorly threaded to have engagement with the threaded downward extension 2Oa of the plunger spindle 20;- Preferably thepitch on the interior and exterior threads of the nut 19 is the same so that it maybe adjusted back and forth to vary the tension of the helical compression spring 21, without disturbing the relative positions of the plunger spindle and the plunger sleeve. rlhe upper vend ot the spindle passes through a bearing in the end wall 17h of the casing so that'by means of the light bearing engagement .between the sleeve 18 and the interior of the casing 17a, and the light bearing engagement between the end -wall' 17b ofthe casing and the adjacent portion of lthe spindle, the plunger has an interior supporting bearing engagement that prevents lateral displacement while permitting tree and easy movement or the plunger. rlhe upper end ot the plunger carries an exterior indicator cap whose closed end wall 2Gb 'forms an intermediate connection between the peripheral wall 20 of the cap and the interiorly supported plunger so that the cap moves in unison with the plunger and diaphragm which torni pressui'e-responsive means whose position is determined by the rise 'and tall ot air pressure thrusting against the yielding spring 2l.

The exterior' wall of the casing, while closely corresponding` to the interior diameter ot the indicator cap 20 is, nevertheless, proportioned to leave a very slight clearance space between these two parts so that there will be no lrictional engagement between them that will be affected by any light accumulation of dust, thereby avoiding impairing the sensitiveness ci" the device.

is it is ot the essence oit this invention that the signal to the motorist should be ot such a nature as Vto be conspicuously visible at a moderate distance from the car, so that at a glance he can tell whether the tires exposed to his view are over or under-inflated, l provide on the exterior wall 22 ot the casing a circumferential display signalingl band 22a ot such visible contrast with the adjacent surfaces as to be plainly noticeable at a distance and or width to allow enough leeway below the appropriate maf-:i-

i mum pressure of the tire to insure its concealment by the cap only when the tire pressure has fallen to the point that will be injurious to the tire. Hence the band in whole or in partwill be displayed so longl as the tire pressure does not tall below normal to the danger point and, in case of excessive air pressure, a portion ot the contrasting wall 22 will be uncovered above the signal band and give plainly visible notice of that condition.

lt will, therefore, be seen that so long as the colored or contrasting band 2:2 is visible the driver is' assured that the normal standard ot air pressure is being maintained in the tires. lWhen the band' is covered by the cap so that the band is no longer visible the driver is warned ot dangerous under-nitiation. rl`he exposure or the contrasting surtace ot the exterior casing wall between the display band and the lower edge or the cap signals over-inflation ot the tire which is just as important when using vballoon tires, practically speaking, as is under-inflation.

What l claim is:

l. A visual safety signal device for pneumatic tires embracing in combination, a compressed air chamber adapted to be permanently attached to a tire stem to maintain communication with 'he interior ot the tire, an impertorate air-sealing diaphragm of nordsee flexible iinpeiwious material secured in said chamber to yieldingly sustain the air pressure of the tire, a spring-pressed plunger arranged to oppose a yielding counterbalancing thrust against the air-pressed diaphragn'i so as to move to and lro within an inclosing casing, the exterior wall of said casing being` 'provided with a conspicuously displayed circumferential band at a distance below its upper end, and a cap secured to the projecting end of aid plunger and overlapping the circumferential wall, said cap eing proportioned to have its lower edge substantially register with the upper portion ot said display band when the air pressure olf the tire is normal, and to expose, above said display band, a contrasting portion o'j the enter-ier wall when the air pressure rites above normal and to conceal said display band when the air pressure 'l'alls below a sate normal pressure.

2. visi l safety signal t'or pneumatic tires, en'ibra v1g an air chamber adapted to be permanently secured to atire stem to continuously admit air trom the tire, an imper'liorate air-sealing diaphragm of flexible impervious material, a plunger casing, a slidable plunger therein spring-pressed to oppose a commer-balancing resistance to the air pressure against the diaphragm, the casing being provided with a circumferential display band ot conspicuously contrasting appearance to render it visible at a distance, an external cap secured to the plunger to move` therewith and so coordinated with the plunger and the display band as to expose the display band to view at normal pressure while concealing it from View when the tire pressure *falls materially below normal.

3. ji visual safety signalV for pneumatic ltires embracing in combination, a comirofsed air chamber, adapted to be permanently secured to a tire stem to afford continuous coniununication with the interior of the tire, a spring-pre sed movable plunger responsive toV variations in the air pressure ot' the tire, and having centralizing bearing engagement with interior portions of the casing, a plunger casing provided with an exterior wall having an exterior display band conspicuously contrasting with the ad- -jacent portion ot the wall surface, a cap whose upper end is closed carried by the plunger in overlapping relation to said eX- terior wall, the cap, plunger and display band being correlated to expose `the display band at normal pressure and to cover the band when the tire pressure falls substantially` below normally sate pressure.

il. A visual safety signal t'or pneumatic tires eniibracing in combination, a compressed air body adapted to be permanently attached to a tire stem to have continuous communication with the interior of the tire, air-sealing pressure responsive means opposing a yielding counter-balancing resistance to the air pressure, an inclosing casing therefor provided with an exterior wall having a conspicuously contrasting display band or' width and appearance to be easily visible at a distance, an external band-concealing cap whose end is closed, a centralizing bearing rod supporting and guiding the cap and connected with the pressure-responsive means to be moved thereby, the lower edge of the cap being disposed to cover from view said display band when the tire pressure is below normal and to uncover it to view when the tire pressure is at normal standard.

5. In a visual safety signal for pneumatic tires embracing in its construction a hollow body adaptedV to be permanently attached to the valve stem of a tire having a valved intake for the admission of compressed air, the combination of a piston casing secured to the open outer end oiC said body and hav-V ing two concentric walls forming separate chambers, a flexible air-sealing diaphragm piston casing, a hollow plunger sldably .mounted in the innerV chamber, a compression spring inserted inside said plunger to exert a yielding thrust of said plunger against the diaphragm in opposition to the compressed air on the other side of the diaphragm, a central post forming partof said plunger and carrying at its outer end a cylindrical cap arranged to overlap the outer wall of said casing and positioned at normal pressure of the tire to expose below its edge a conspicuously visible signal band which is concealed from view when the tire pressure falls below normal, and a sleeve of exible material connected with said post and with the outside of the inner wall of the casing to prevent the entrance of dust, substantially as described.

ln witness whereof, I have subscribed the above specification.

JoriN n. KENNEDY. 

